Question

tg150-cos780+sin330
прошу помогите

Answer 1

$tg150-cos780+sin330=tg(180-30)-cos(360 cdot 2+60)+$
$displaystyle +sin(360-30)=-tg30-cos60-sin30= - frac{ sqrt 3}{3}- frac{1}{2}- frac{1}{2}=$
$displaystyle = - frac{ sqrt 3}{3}- frac{3}{3}= frac{-(sqrt 3+3)}{3}$